Dunno about other places but the local town (about 5000 population) has all 3 major parts chain stores within 5 blocks of each other. AZ, Oreilly and Advance, if you're standing at Oreilly and throw a rock, you can easily hit one of the other two depending on which direction you throwed.
Now to me, that's not good business. How does one or the other stay in business if the same exact brands and prices are all right there together? Perhaps they're just all tax write-off's for the company, or parent company? I don't know.
I don't use any one of them specifically, just whichever is easier to get to at the time. Sometimes one might be sold out of a filter so I'll have to go to another. If I'm riding the "hog" (scooter) into town, Oreilly is usually the go-to, easier to get to without hitting much of the main highway (scooter only runs about 60mph). You better be able to run 85+ if you get on the major highway, better to be able to make 100. People are idiots (speed limit 45 most run 55 and more than a few are 70+). In a hurry to drop the kids off at soccer practice after school, and in a BIG hurry in the mornings to drop them off at school before work, or wal-mart shopping.
Anyway there is also a local store that is indpendent and I sometimes go there as well. They've got more big truck stuff so if I need exhaust tubing or clamps or whatever, they are the only game in town.
The big "3" all have asphault drives that are destroyed by the leaking chevy's that are commonly parked there. An occasional dodge as well but they're usually getting transmission fluid, ball joints, or brake rotors. There's a local guy who is there every single day buying something for his Cummins powered dog truck, but he thinks it's gold. Good for him. It's ok to be proud of what you drive. Just saying. Mine are all wore out junk, by the way. 2003 is the newest, the others are way older and way more miles (and a LOT less paint!).
The big 3 have a "performance" section, where they keep one carburetor, some header gaskets and AZ has a couple K&N filters. If I go in any of them looking for a small block ford anything, they laugh me out the door. That's fine. I have a computer and will continue to order as needed. But if I had a small block Chevy, they'd likely have it in stock; although likely to be chinese garbage that is grossly overpriced.